1. Field of the Invention
The present invention relates to an embroidering apparatus mountable on a sewing machine bed.
2. Description of the Prior Art
Known embroidering apparatus comprises a fixed rail mounted on a sewing machine frame, a movable rail extending in criss-cross relation to the fixed rail, and an embroidery frame movable back and forth and laterally along the fixed and movable rails. A piece of cloth on which a pattern is drawn after an original pattern is placed under tension on the embroidery frame, which is manually moved around so as to allow a sewing needle as it moves up and down to follow the pattern on the piece of cloth. It is not an easy task to pattern a figure in detail after a model on the cloth as correctly as the operator desires, or there is always a tendency for the pattern to be drawn somewhat differently from the model pattern. Another disadvantage with the prior embroidering apparatus is that it is difficult to move the embroidery frame in order for the needle to pierce the cloth exactly at desired positions, resulting at times in embroidered works which are not patterned after the model.
Another type of embroidering apparatus comprises a tracing needle which traces a fixed original pattern while the tracing needle is moving with an embroidery frame. Such embroidering apparatus is disclosed in U.S. Pat. No. 2,894,468, issued July 14, 1959 to Walter Nohl, for example. The embroidery frame may be either movable back and forth and laterally along crossing rails, or supported on a pantograph mechanism of parallel links which is expansible and collapsible for allowing back-and-forth and lateral movements of the embroidery frame. The tracing needle is attached to a rod extending from the embroidery frame for movement therewith. In operation, the rod is gripped at an end portion thereof adjacent to the tracing needle and moved so as to enable the latter to follow the original pattern. With this arrangement, it is not necessary to draw a pattern on a piece of cloth after the original, and the patterning can be effected easily and reliably as the tracing needle follows the original while kept in contact therewith or closely thereto. However, since the tracing needle and the embroidery frame move in unison, leftward movement of the tracing needle causes the sewing needle to be located rightward in the embroidery frame and forward movement of the tracing needle causes the sewing needle to be located rearwardly in the embroidery frame, making an embroidered pattern look inverted. Such an inverted pattern renders it quite difficult for the operator to ascertain whether the original model is being followed to a nicety while in the embroidering operation. There has been known an apparatus having a mechanism for orienting an embroidered work in the same direction as the original pattern. Inclusion of such an additional mechanism makes the apparatus complex in construction. Furthermore, since the rod is relatively slender and flexible, it tends to flex due to frictional resistance between the cloth placed on the embroidery frame and a throat plate, with the results that movement of the embroidery frame will not correctly reflect that of the tracing needle, and hence the resultant embroidered pattern will not look much like the original pattern.
The prior embroidering apparatus as described above are designed to embroider a piece of cloth only with stitches in one and the same directions, and are unable to produce embroidery works with stitches in any different directions, such as a pattern of fur of an animal. To cope with this, there have been devised embroidering apparatus having an embroidery frame that is rotatable as well as movable back and forth and laterally to produce an embroidered pattern with varying stitches. One such embroidery apparatus is manually actuatable, while the other is electrically controllable. The former type is disclosed in U.S. Pat. No. 3,082,721, issued Mar. 26, 1963 to Luigi Bono, and the latter type is disclosed in U.S. Pat. No. 4,195,581, issued Apr. 1, 1980 to Naoki Ohara, for example. The manually operable apparatus has suffered from problems in that a pattern should be drawn on a piece of cloth after a model, a procedure which can produce a rough contour of the model but fails to transfer exactly the same pattern on the cloth, and hence the original pattern, the figure drawn on the cloth and the embroidered pattern are likely to look differently. Furthermore, the operator should be trained and skilled sufficiently in rotating, moving back and forth, and moving laterally the embroidery frame or a support frame therefor at the same time. Otherwise, embroidering a pattern exactly after a model would not be possible. The electrically-operated embroidering apparatus comprises an actuator including three pulse motors for rotating, moving back and forth, and moving laterally an embroidery frame, and a control unit for electrically controlling the pulse motors. The embroidering apparatus is thus quite complex in structure and expensive to construct.